1. Field of the Invention
The present invention relates generally to an electrode, an electronic component and a substrate, and more particularly, to a column-like electrode to which a large voltage is applied, an electronic component using this electrode, and a substrate.
2. Description of the Related Technology
For example, a large voltage is applied to a power source component and a power source module. The electronic component to which the large voltage is thus applied involves using, as shown in FIGS. 8A and 8B, a column-like butt electrode 50 or, as depicted in FIGS. 9A and 9B, a square-pole-like butt electrode 51.
Note that throughout the FIGS. 8A, 8B and FIGS. 9A, 9B, the numeral 52 designates an electronic component, 53 represents a substrate, 54 denotes a solder, and 55 indicates an air void.
In the conventional butt electrodes 50, 51, a column-like copper bar member taking a cylindrical shape, a square-pole-like shape, etc. is cut off to a predetermined length and used in an as-cut state. Namely, joint surfaces 50a, 50b, 51a, 51b and outer peripheral surfaces 50c, 51c, with the electronic component 52 and the substrate 53, of the butt electrodes 50, 51 are employed in a way that does not apply any other working to these surfaces.                [Patent Document 1] JP 09-162220 A        
The conventional butt electrodes 50, 51 have the problem, wherein disc-shaped air voids 55 remain within a solder 54 between the joint surfaces 50a, 50b, 51a, 51b and the electronic component 52 or the substrate 53.
The air contained in the solder paste is gathered, whereby voids 55 are formed.
It is to be noted that FIGS. 7A, 7B and FIGS. 8A, 8B illustrate only the air voids 55 between the joint surfaces 50b, 51b of one of the butt electrodes 50, 51 and the substrate 53. The air voids 55 also remain within the solder 54 between the joint surfaces 50a, 51a of the other of the butt electrodes 50, 51 and the electronic component 52.
Thus, if the air voids 55 remain between the joint surfaces 50a, 50b, 51a, 51b of the butt electrodes 50, 51 and the electronic component 52 or the substrate 53, an effective joint area between the butt electrodes 50, 51 and the electronic component 52 or the substrate 53 is reduced. In this case, such a problem arises that joint strength between the butt electrodes 50, 51 and the electronic component 52 or the substrate 53 decreases.
Further, areas of the joint surfaces 50b, 51b, with the substrate 53, of the butt electrodes 50, 51 are large, and hence, if the substrate 53 becomes flexural for some reason, a comparatively large bending moment is generated at joint portions between the butt electrodes 50, 51 and the substrate 53.
Thus, if the large bending moment is generated at the joint portions between the butt electrodes 50, 51 and the substrate 53, there might be a possibility in which a crack occurs in the joint portion.
Further, as described above, the joint faces 50a, 50b, 51a, 51b of the butt electrodes 50, 51 are smooth. Therefore, an anchor effect of the solder 54 is difficult to occur with respect to the joint surfaces 50a, 50b, 51a, 51b. 
In this case, interfacial peeling occurs between the joint surfaces 50a, 50b, 51a, 51b of the butt electrodes 50, 51 and the solder 54, resulting in such an problem that the joint portion becomes fragile against a impact of dropping.
Moreover, the joint surfaces 50a, 50b, 51a, 51b of the butt electrodes 50, 51 are smooth, and hence there is a problem, wherein the solder 54 is repelled. In this case, the joint strength is lowered.
It is an object of the present invention, which was devised in view of these problems, to provide an electrode, an electronic component and a substrate that are capable of eliminating the air voids generated within the solder between the joint surfaces of the electrode body and the electronic component or the substrate, thereby restraining a decrease in the joint strength between the electrode body and the electronic component or the substrate.